1. Field of the Invention
This invention relates generally to a search and rescue radar transponder which sends out a coded signal of distress at radar frequencies in response to a search radar pulse, and in particular, to a search and rescue radar transponder having an improved housing assembly which reduces the overall size, increases the operability and ease of use and reduces manufacturing costs.
2. Description of the Prior Art
Search and rescue radar transponders (SART) are known in the prior art. Typically, search and rescue transponders are carried aboard a ship and can be removed, transported and installed in a raised location aboard a life raft. Conventional search and rescue transponders are elongated and bulky due to the required number of batteries therein, shaped much like a 5-cell flashlight, making them often awkward to use in a survival situation. A search and rescue radar transponder oftentimes is the primary means for locating an ocean or water survival craft, using a standard ship's search radar. Typically a SART would operate on 9-gigahertz frequency band and send a series of pulse responses once interrogated by a conventional shipborne or airborne search radar. A series of blips are received from the SART to the radar screen aboard the searching ship, which is readily recognized as a distinctive signal of distress.
One primary concern is the fact that in a survival situation, especially in cold water, the user will typically have on very bulky clothing, including gloves. Ease of activation of the SART is crucial to insure that the device is activated by the user at the proper time. Agile manipulation is also required with respect to quickly disconnecting a SART from a ship for connection to a raft. The overall size and configuration of a SART is very important to get the most battery power from the least volume because the SART is hand activated, and at the same time should take up very little storage space when not in use.
The present invention provides for an improved SART that has an improved housing assembly which is waterproof and quite durable, is easy to manufacture, gives maximum battery storage space for the size and volume of the housing assembly, can quickly be mounted or disconnected from either shipboard or a life raft, and can easily be activated by a user wearing bulky gloves. The present invention further includes a unique retaining ring that joins the upper and lower housings together without screws or other labor intensive fasteners, reducing the overall cost of manufacture. The retaining ring does not induce cold flow plastic problems because the joined components are not under pressure.